Method and mobile station for route guidance

ABSTRACT

A mobile station ( 1 ) serves in association with a corresponding method to guide a user, especially a pedestrian, to a destination. For this purpose an on-line service computes a travel route on the basis of user data concerning the start point and destination and transmits route data to the mobile station in the form of route destinations for stages of the route. Each route destination contains at least one specification of direction and a destination name. The mobile station ( 1 ) signals the target direction and the name of the destination of the route to the user via internal optical and/or acoustic output means ( 7 ). The route data are output in stepwise manner in the form of a series of stages of the route and the user confirms reaching a current route destination by means of an input into the mobile station ( 1 ). In this way the output of the route data is updated. In order to be able to define a target direction for the current route destination an appropriate application software package and a direction indicator ( 22 ), preferably a compass responding to the earth&#39;s magnetic field, are integrated in the mobile station ( 1 ).

DESCRIPTION

[0001] The invention relates to a method of route guidance for a personwith a mobile station which is connected via a mobile telephone networkto a special on-line service. The on-line service provides geographicinformation data for route guidance which a person on the move, such asa pedestrian, cyclist or the like, calls up for automatic route guidanceto a desired destination. The invention additionally relates to anextension of the technical fittings for a mobile station which correctsthe optical and/or acoustic output and utilisation of the transmittedinformation data. Moreover, the invention can also be applied in anytype of vehicle. In the present document the term “mobile station”describes any mobile device to which a bidirectional connection to amobile telephone network can be established, for example a mobiletelephone for a cellular radio communications network.

[0002] What is known as the global positioning system (GPS) is used toguide a vehicle in an unfamiliar region to its destination. If a GPSreceiver in the vehicle receives simultaneously at least three GPSsatellites the receiver can determine from the propagation delay of thesignals its local position exactly to within about 20 m to 100 m.Moreover, by exploiting the Doppler effect in moving vehicles the speed,course and other navigational variables may be determined. Starting fromthe computed position a dead reckoning navigation unit havingappropriate sensors for the motion of the vehicle determines route dataon the actual direction of motion and on the distance covered.

[0003] Only once a local computer has entered the route data into anelectronic map is it possible to relate one's own position to theproximate environment. The computer requires access to a databasecontaining a substantial volume of geographic information in order toselect the information for the electronic map in accordance with thedesired destination. After the route has been computed this is output byacoustic or optical means.

[0004] The application of this system for the provision and detailedvolume of data would not be just a problem for the pedestrians andcyclists. For the geographic information alone the computer needs anon-volatile local storage medium having high storage density such as aCD-ROM or hard disk offering a storage capacity of some hundreds ofmegabytes. Accordingly, the fittings are substantial and costly and dueto their volume, weight and energy consumption are not well suited to amobile station such as a mobile telephone. Over and above that, periodicupdating of the information when local changes occur has to be ensured.

[0005] As an alternative to this the French company Webraska MobileTechnologies SA runs a navigation service on the Internet(http://webraska.com) with a server which substantially possesses acartographic database and a program for the computation of travelroutes. The delivery of this service, in particular the computation ofpersonal travel routes can be requested inter alia by network connectionvia a mobile station. The technical design of the service is set out inpublication WO 98/45823. By means of appropriate textual, graphic andacoustic data entered into his/her mobile station the person transmitsinformation about the desired destination to the server. The mobilestation also has a positioning device, such as for example theaforementioned GPS receiver, and determines its own local positionautomatically. Alternatively, a known GSM network positioning facilitycan be used which calculates the current position on the basis ofdistances to nearby base stations in the mobile communications network.However, the data on the starting position can also be entered by theperson him-/herself in the form of text and/or graphics or acoustically.

[0006] After receiving the position and destination data the navigationservice computes a corresponding personal travel route and transmitsthis to the mobile station as route coordinates in vector form during atransmission period. That means the entire distance is transmitted as aseries of coordinates for route segments so that the geometric patternof the route is stored temporarily by means of coordinates in the mobilestation and can be illustrated on a mobile station display by means ofstraight route segments and curved segments.

[0007] The wireless data interchange between the mobile station and thenavigation service ensues in accordance with the Internettelecommunications application WAP=wireless application protocol. Thisis optimised for use in wireless data communications and instead oftransmitting complex structured web pages transmits only text and simplegraphics.

[0008] The positioning device periodically determines the currentposition of the mobile station and a microcomputer compares this withthe local route coordinates on the transmitted travel route. In this wayconstant route guidance including display of the current position in amap is possible in real time and the microcomputer can immediatelyidentify and output departures from the travel route. In order to avoidthe person having to constantly observe the graphic display there is thepossibility of indicating a forthcoming change of route direction bymeans of additional acoustic or optical outputs, for example in a mobiletelephone by lower image resolution. The solution, however, imposeslower requirements on the local equipment with regard to the computerand storage capacity than other navigation systems so that routeguidance for pedestrians and cyclists can be implemented. In all of theembodiments described the microcomputer is continuously makingcomparisons regardless of the complexity of the course of the travelroute, for example at intervals of seconds, between the current localpositional data and the route coordinates of the computed travel route.This is disadvantageous as was also the case for the solution describedat the outset. If the mobile station moves for a relatively long time onthe same road or the same route the computer and positioning device arecarrying out many redundant activities which drain the battery powersupply without the accuracy of the route guidance rising. This is aparticularly unsatisfactory state in the case of a mobile telephonehaving a compact power supply.

[0009] Moreover, as a consequence of the detailed presentation of thetravel route for all roads or routes not running in a straight line theroute coordinates for several route segments are transmitted. Thisincreases the cost of data transmission to the mobile station. As aresult of the limited transmission bandwidth of the mobilecommunications network, however, only a small volume of data can betransmitted in an acceptable time so that redundancy in the data volumesshould be avoided. Moreover, only a limited amount of energy isavailable to a user without a vehicle for determining the route.

[0010] All of the aforementioned solutions require GPS signals in eachtime interval simultaneously from at least three GPS satellites. Thisassumes constant good reception of these satellites and is difficult toensure particularly in densely built-up areas. In the event of defectivereception errors occur in the route guidance, particularly in regions inwhich the direction of motion towards the destination changes at shortintervals.

[0011] Numerous publications disclose the use of electronic compasssensors for navigation purposes. The company Precision Navigation, Inc.,Canada, for example, manufactures such sensors. Instead of a rotatablymounted magnetic needle such modules use two inductors oriented at rightangles to one another in order using the earth's magnetic field todetermine the orientation of a device relative to the points of thecompass. In a computation process the orientation can be calculateddirectly in degrees. Accuracies of less than 5° can be achieved at lowcost and with comparatively little effort.

[0012] The aim of the invention is, on the one hand, to provide a methodin which at no or only little additional cost for equipping the mobilestation for low energy consumption and for low transmission capacity aroute guidance system having a mobile station and a communications linkto an on-line service, in particular for pedestrians, is possible. Onthe other hand, it is the aim of the invention to extend the technicalfittings of a conventional mobile station at low additional cost in sucha way that the user can be guided conveniently from a starting point toa destination.

[0013] The solution according to the invention is based on the idea thatneither geographical route information nor means for defining the localposition are present in the mobile station. Accordingly, the userconducts a dialogue via the mobile station with the on-line service inorder to transmit information on his/her current local position andhis/her desired destination. The on-line service uses geographicinformation from a database in order to determine the positional datafor the current position and the desired destination, computes apersonal travel route and transmits corresponding route data to themobile station.

[0014] In contrast with the known solution the on-line servicepreprocesses the route data in the form of a series of stages of theroute having discrete route destination s. The route destination s serveto orient the user and depend on prominent points on the route, inparticular on branching of the route to the user's destination. As theminimum data for each stage the on-line service transmits in each caseonly a specified direction and the designation of the route destination.Prominent points on the route for discrete route destination s are inparticular branching points on the travel route which require, forexample, leaving a road used so far, crossing a square or even passinglandmarks, memorials and public buildings. At route destination s theuser usually selects a new route direction. The mobile station outputsthe received route data for each route destination optically and/oracoustically as a destination direction and destination name. Once theuser has reached his/her current route destination by enteringconfirmation into the mobile station he/she requests output of thefollowing route destination.

[0015] The present invention makes use of the knowledge that for guidinga person to a destination it is not absolutely necessary to constantlytrace one's own path in a map against the surroundings of the routetravelled nor is other information in line with scale on the course ofthe travel route needed. Sufficiently exact guidance to the destinationis possible solely in that starting from his/her current position theuser is given an unambiguous specification of direction and thedesignation of the next route destination. This reduces the transmissioncapacity for transmitting the route data. If the route runs innon-linear manner because, for example, the road takes a curved courseno additional route destination s need be transmitted as long as thetravel route does not depart from the road defined as the stage.

[0016] Details on the length of path of stages of the route or of thetotal distance are helpful but not essential if the user receivesunambiguous destination names.

[0017] Conventional means for dead reckoning navigation can be dispensedwith because the mobile station outputs the route data in stepwisemanner in the sequence of the stages of the route and only updates theoutput when the reaching of the current route destination is confirmed.

[0018] It is highly advantageous that the user can already start on theway using the current specified destination before transmission of thedata for the entire travel route is ended.

[0019] According to an advantageous development of the invention theuser in a first step establishes a communications link with the mobilestation to the on-line service in order to start a dialogue. In doing sothe on-line service asks for the positional and destination informationneeded for route guidance. The positional data can be determined both ina speech dialogue as well as in a dialogue using written and/orgraphical input. Advantageously, however, speech information from theuser is compared with geographical information from the database, thelocal position is defined with the aid of prominent points in thesurroundings through targeted interrogation by the on-line service andthe corresponding positional data are read out from the database.

[0020] The on-line service conducts the speech dialogue either through aperson or advantageously using a speech computer. Following a roughstatement of the user's position the speech computer selectivelygenerates on the basis of information from the geographical databasequestions to specify more precisely and qualify the positional anddestination data.

[0021] According to a further advantageous version of the invention theon-line service obtains information from the mobile communicationsnetwork operator on the position of the network access point. That is tosay it uses the knowledge of the position of the base station of thecell through which the user's mobile station is logged into the mobilecommunications network in order to discover automatically roughinformation on the local position of the user.

[0022] This has the advantage, especially in a large city having a densecell network that already without help from the user the zone of theposition can be pinned down and the name of the city and district needno longer be enquired about. A question about the name of a street or asquare already serves in many cases to pin the position down. A furtherquestion for the name of an intersecting or branching street would thendefine the user's position with sufficient accuracy within a short time.This too is carried out by preference in a speech dialogue on grounds ofconvenience.

[0023] The route data determined by the on-line service can betransmitted in full to the mobile station immediately after it has beengenerated and then stored temporarily in the mobile station. On the onehand, this shortens the busy time of the transmission channel and hencelowers connection costs. On the other hand, however, this requiresadditional free memory capacity in the mobile station.

[0024] In order to be independent of the level of technical fittings inthe mobile station, as an alternative to this the on-line service canalso advantageously store the route data temporarily and transmit it instepwise manner in the sequence of the stages of the route. Once theuser has reached his/her current route destination, by inputting aconfirmation into the mobile station he/she calls for the route data forthe following route destination from the on-line service. The on-lineservice transmits corresponding route data and the mobile stationoverwrites the previous contents of the memory.

[0025] In addition to the known functional elements for carrying outtelecommunications, the mobile station according to the invention has adirectional indicator which provides direction data in accordance withthe orientation of the mobile station relative to the points of thecompass in order to define a target direction to the current routedestination at any time. A processor which is already present in eachmobile station compares the directional data with the route data whichcontain the specification of direction for the current stage.

[0026] Depending on the construction of the invention at least oneoutput part signals optically and/or acoustically a departure from thepresent orientation of the mobile station from the target direction. Asan alternative to this an output part outputs optically and/oracoustically together with the name of the current destination a targetdirection related to the orientation of the mobile station. For thispurpose the optical and/or acoustic output components present in themobile station are preferably used. In the case of acoustic output asimple sound signal or speech can be output.

[0027] By using the directional indicator a decisive disadvantage ofroute guidance devices using a GPS receiver is avoided. These can onlyrecognise the direction of movement of the user once the latter haspossibly moved in the false direction. In the solution according to theinvention, however, the correct target direction is already outputtogether with the first route destination. Optical output of the targetdirection and destination name has the advantage of being readilyperceptible even at high noise levels, as is the case, for example, onstreets with traffic. Acoustic output, speech output for example, isadvantageous at twilight or for people who have difficulty making outoptical displays.

[0028] In order to allow unambiguous guidance of the user with the aidof the target direction and destination name the mobile stationpossesses a program advance circuit. On reaching the current routedestination this is actuated in order to update the output.

[0029] An exemplified embodiment of the subject matter of the inventionis illustrated in the drawings. These show:

[0030]FIG. 1 a block diagram of the mobile station according to theinvention,

[0031]FIG. 2 a block diagram for access of the mobile station to theon-line service and FIGS. 3a-4 b examples for the optical output ofroute data for the computed travel route.

[0032]FIG. 1 shows a block diagram having essential functional elementsin a mobile station 1. This has a processor 2 to which for the opticaloutput of information a display 4, eg a liquid crystal display having adot matrix, and a keyboard 2C) 6 are connected. In practice, dependingon the design of the mobile station 1 the processor 2 can be formed of asingle processor or from several connected processors. It implements inreal time operation the known telecommunications functions and possessesstorage means such as a memory 8 for the temporary storage of data. Alltemporary data arising from an existing network connection such asadditional information or information on value-added services receivedover the network are stored in this memory. Further connected to theprocessor 2 are an audio reproduction branch AP containing adigital-analogue converter 10 and a loudspeaker 12 and a microphonebranch SP containing an analogue-digital converter 14 and a microphone16. The audio reproduction branch AP outputs acoustically telephoneconversations and information for value-added services. A HF transceiver18 having an antenna 20 establishes the communications link to a mobilecommunications network NET.

[0033] The structure described so far corresponds to that of aconventional mobile telephone.

[0034]FIG. 2 shows the access to the mobile communications network NETvia a network access point BS which in the present case is a basestation of a cellular communications network 2.

[0035] For the transmission protocol between the mobile station 1 andthe base station BS what is known as the “wireless application protocol”or a different Internet communications protocol for a mobile station canbe used for example.

[0036] The onward connection then leads, for example, via a protocolconverter known as a “WAP gateway” to a server of an on-line service(OS). The on-line service (OS) is connected to the database whichcontains comprehensive geographic information.

[0037] For the medium between the mobile station 1 and the base stationwhat is known as the “general packet radio system” GPRS also comes intoconsideration in future. This carrier service is known for datainterchange at higher data rates between a mobile telephone and a mobilecommunications network The known “circuit switched data” CSD isalso-suitable.

[0038]FIGS. 3a and 3 b show the optical presentation of the transmittedroute data on the display 4 according to a simple embodiment of theinvention. In this application the mobile station can be a mobiletelephone with conventional fittings. The display 4 contains exclusivelyinformation in the form of individual characters. In a position line 22is the designation of the starting position for the current stage. Inthe present example these are the street name and the number of thehouse at which the user is standing at the beginning of route guidance.The downward pointing arrow indicates that the user on “Oxfordstreet”must move in the direction of lower house numbers in order to reachhis/her current route destination. In this manner in the present examplea specification of direction for the first route destination isachieved. In a destination line 24 the display 4 additionally shows thename of the current route destination, in the example the branching of“New Bond Street” from “Oxfordstreet”, that is to say the point on theway at which the route reaches a branching point and a change ofdirection is needed. In front of the name of the current routedestination there is an arrow to specify the new direction. In thepresent case the new target direction is about 135° to the right withreference to the present one. Under the destination line 24 there aredetails about the following stages of the route.

[0039] Advantageously the paths of the stages of the route aresupplemented by distance information. This supports the route guidanceand provides information about the length L of the total travel route.The lower edge of the display 4 provides information 26 and 28 on thecurrent effects of the corresponding functional keys on the mobilestation. On reaching a route destination the functional key 26, forexample, is actuated in order to update the information in the display 4as shown in FIG. 3b for the following route destination.

[0040] In the special embodiment of the invention according to FIG. 1 inaddition to the named standard functional units 2 to 20 the mobilestation 1 contains a directional indicator 30, for example a magneticcompass or preferably an electronic compass sensor as was described inthe introduction. The use of a magnetic compass having a mechanicaldisplay certainly has the advantage that it requires no energy andcalibration to operate. However, attribution of a specified directiontransmitted by the on-line service is relatively difficult.

[0041] An electronic compass sensor, on the other hand, supplies data tothe processor 2 on the current orientation of the principal axis of themobile station 1 as a function of the earth's magnetic field. Aninternally stored application program calculates from the transmittedspecification of direction and the data on the current orientation theactual target direction to the route destination for optical and/oracoustic output.

[0042] Advantageously the mobile station 1 also possesses means whichindicate to the user a departure of the operating position from thehorizontal in which the directional indicator 30 operates defectively.

[0043]FIGS. 4a and 4 b show a optical display of transmitted informationprepared by the processor 2 with inclusion of the directional indicator30. A optical display of direction 32 shows the user by means of adirectional arrow 34 the target direction of the current routedestination in the destination line 24 which the processor 2 hascomputed from the specified destination in the route data and the sensordata of the direction indicator 30 on the current orientation of themobile station. The direction display 32 itself has a frame with a fixeddirection arrow which coincides with the principal axis of the mobilestation. This is important, for example, when the shape of the housingof the mobile station departs distinctly from the shape of aconventional mobile telephone. The mobile station is pointing at theroute destination when the fixed direction arrow and the directiondisplay 32 are pointing in the same direction.

[0044] At the same time the display 4 shows in the position line 22 thestarting point, that is to say the start of the current stage.

[0045] For example, the user is located in Oxford Street in front ofhouse number 34 and would like to go to a restaurant “Pizza Napoli”.Once he/she has established a connection to the on-line service OS anoperator of the on-line service OS acquires both the positional data aswell as the destination data. In doing so the operator uses an exactgeographic description of the location in the database DB. A server ofthe on-line service OS computes the travel route and transmits thecorresponding data automatically to the mobile station 1.

[0046] The mobile station I files the received route data in the memory8. Since the travel route is made up of a series of route destination s,the processor 2 first of all calls up from the memory 15 the data forthe first route destination. In the example chosen the first routedestination is in Oxford Street, 100 m from the current position and,for example, presents a junction or intersection with New Bond Street.In addition, the processor 2 uses the direction data from thedirectional indicator 30 in order to identify the orientation of theprincipal axis of the mobile station 1. On the basis of the route dataand the orientation the processor 2 determines the target direction tothe current route destination and indicates this in the display 4 bymeans of the direction symbol 34. That is to say, regardless of theorientation of the mobile station 1 in the horizontal plane thedirection symbol 34 always points in the correct direction. Furthermore,the processor 2 outputs the current destination name for the currentroute destination in the destination line 24.

[0047] If the memory contains no more route destination s rout guidanceis terminated automatically.

[0048] According to a development of the invention it is also possibleto output the information about the travel route acoustically, forexample via the audio reproduction branch AP in the mobile station 1.

[0049] The user can also communicate arrival at a route destination tothe mobile station 1 acoustically via speech input through themicrophone branch SP. In doing so a speech recognition program servesthe processor 2 to recognise and process the speech.

[0050] For interchange between the mobile station and the on-lineservice OS it is not essential in the method according to the inventionto use a speech channel. Transmission is possible on any transmissionchannel for what are known as value-added services (VAS).

[0051] The solution according to the invention has the substantialadvantage that it can be implemented with a minimum of additionalexpense and volumetric capacity in a mobile station. In the simplestcase the minimum requirement for carrying out the invention is aconventional mobile station having a WAP protocol installation.

1. Method of route guidance for a user with the aid of a mobile station(1) in which the user is connected via the mobile station (1) to anon-line service (OS) which has access to an electronic database (DB)containing geographic information in order to transmit from the userinformation on his/her local position and his/her destination and inorder to request from the on-line service (OS) route data for individualroute guidance, wherein the mobile station (1) outputs the route dataoptically and/or acoustically, characterised in that the on-line service(OS) preprocesses the route data as a function of the branching of thetotal route to the user's destination as a series of stages of the routewith discrete route destinations and to identify each stage transmits tothe mobile station (1) in each case a specification of direction and adestination name for the route destination.
 2. Method according to claim1, characterised in that the route data additionally contain details ofthe distance of the entire route and/or of stages of the route. 3.Method according to claim 1, characterised in 'that the mobile station(1) outputs the route data in stepwise manner in the sequence of thestages of the route with corresponding specifications of direction anddestination names and that the user confirms the reaching of a currentdestination of a stage with an input to the mobile station (1) in orderto update the output of route data.
 4. Method according to claim 1,characterised in that the on-line service (OS) transmits the route datain stepwise manner in the sequence of the stages of the route so thatthe user can move towards the first route destination already during thetransmission of route data.
 5. Method according to claims 3 and 4,characterised in that the on-line service (OS) stores route datatemporarily and that the user on reaching the current route destinationrequests the transmission of the data for at least one following stagefrom the on-line service (OS) by means of an input into the mobilestation (1).
 6. Method according to claim 1, characterised in that theon-line service (OS) conducts a dialogue with the user via a cellularcommunications network (NET), a network access point (BS) and the mobilestation (1) in order with the support of the database (DB) to determinepositional data and destination data for the current location of theuser and for the desired destination of the user.
 7. Method according toclaim 6, characterised in that the on-line service (OS) has informationabout the location of the network access point (BS) to thecommunications network (NET) and uses this information in the dialoguefor the rough determination of the position of the user.
 8. Methodaccording to claim 6, characterised in that an automatic speechrecognition system controls the dialogues for the determination of thepositional data and the destination data.
 9. Method according to claim1, characterised in that a direction indicator (22) in the mobilestation (1) provides a reference direction in order to define a targetdirection to the respective current route destination.
 10. Methodaccording to claim 9, characterised in that the direction indicator (22)provides directional data in accordance with the orientation of themobile station (1) relative to the points of the compass, that aprocessor (2) compares these directional data with route data whichcontain the specification of the direction for the current stage andthat at least one output component (4, AP) signals any deviation in thecurrent orientation of the mobile station (1) from the target directionby optical and/or acoustic means.
 11. Method according to claim 9,characterised in that the direction indicator (22) provides directionaldata in accordance with the orientation of the mobile station (1)relative to the points of the compass, that the processor (2) determinesthe deviation in orientation from the current specification of directionand jointly with the destination name of the current route destinationoutputs optically and/or acoustically a target direction relative to theorientation of the mobile station (1).
 12. Method according to claim 1,characterised in that the route data are transmitted on a data carrierchannel which is specially provided for the transmission of data forvalue-added services.
 13. Mobile station (1) for guiding a user to adestination with the aid of an on-line service (OS) which via a wirelessconnection to a communications network (NET) transmits route data for atravel route, wherein the mobile station (1) contains a processor (2)having means of storage (8) for the temporary storage of the route datatogether with appropriate application software which outputs the routedata optically and/or acoustically, characterised in that a directionindicator (22), preferably a compass responding to the earth's magneticfield, is integrated in order to be able to define a target directionfor the current route destination.
 14. Mobile station (1) according toclaim 13, characterised in that the direction indicator (22) generatesdirectional data for the processor (2) in accordance with theorientation of the mobile station relative to the points of the compassand that the processor (2) compares the directional data with thespecifications of direction contained in the route data for the currentroute destination and signals any departure of the present orientationof the mobile station (1) from the target direction via at least oneoutput component (4, AP) optically and/or acoustically.
 15. Mobilestation (1) according to claim 13, characterised in that the directionindicator (22) generates directional data for the processor (2) inaccordance with the orientation of the mobile station (1) and that theprocessor (2) optically and/or acoustically outputs the currentspecification of direction contained in the route data taking intoaccount the present orientation of the mobile station as targetdirection relative to the current route destination together with thecurrent destination name.
 16. Mobile station (1) according to claim 13,characterised by a forward switching program with which the user updatesthe output of the route data on reaching a route destination.
 17. Mobilestation (1) according to claim 13, characterised by a forward switchingprogram with which on reaching a route destination the user builds up aconnection once again to the mobile communications network (NET) for theon-line service (OS) in order to call up data for further routedestinations.
 18. Mobile station (1) according to claim 1, characterisedin that the latter is a mobile telephone.